Sepsis is a significant healthcare issue due to its high frequency of occurrence and high mortality rate in hospitals. Sepsis is characterized by a whole-body inflammatory state, called a systemic inflammatory response (SIRS), and by the presence of a known or suspected infection. The immune system may cause this inflammatory response as a consequence of microbes in the blood, urine, lungs, skin, or other tissues, for example. One of the leading causes of sepsis is a bloodstream infection (BSI). BSI is most commonly diagnosed by a blood culture, in which a sample of blood is incubated with a medium in an atmosphere controlled to promote bacterial growth.
Current automated blood culture systems can take 12-48 hours to detect the presence of infectious microorganisms in blood and can take up to 5 days to rule out the presence of any infectious microorganisms. It can take up to another 12-48 hours to identify the infectious microorganisms by sub-culturing the positive blood culture and performing identification and antimicrobial susceptibility tests. These results can be too late to alter the treatment course and result in the death of the patient.
One approach to faster bacterial time to detection (“TTD”) is dividing the sample liquid together with growth media into a large number of smaller volume samples that are contained in closed small volume compartments (see U.S. Pat. Nos. 5,770,440 and 5,891,739 to Berndt, the entire contents of which are both hereby incorporated by reference herein). The added steps required to segregate the blood/media sample into smaller volume samples can be difficult and time consuming. Additionally, designing a product to address this increased workflow can be limited by considerations of manufacturability and cost. Consequently, a small-volume compartment BSI product design that is easy to manufacture, cost effective, less time-consuming to use and reduces TTD in a clinical sample is desired.